1. Field of the Invention
The invention relates to a back light structure and a keyboard with back light, and especially relates to a back light structure, whose light-emitting components are disposed inside its light guiding plate, and a keyboard with back light having the back light structure.
2. Description of the Prior Art
Conventional keyboards with back light usually use a light guiding plate with light-emitting components. If the light-emitting components are disposed inside the light guiding plate, for example in through holes formed insides the light guiding plate, a flexible circuit board electrically connected to the light-emitting components needs to be disposed under the light guiding plate. Furthermore, for increment of light usage, the keyboard with back light also includes a light reflection sheet which is also disposed under the light guiding plate. In order to avoid light leakage from a side edge of the light guiding plate, the light reflection sheet usually needs to totally cover the lower surface and all side edges of the light guiding plate. However, in such configuration, the light reflection sheet also needs to cover the flexible circuit board, leading to a relative protrusion of a portion of the light reflection sheet covering the flexible circuit board. That is, the thickness of the back light structure of the keyboard with back light at least includes a summation of the thicknesses at least of the light guiding plate, the flexible circuit board, and the light reflection sheet. Hence, in such back light configuration, the thickness summation becomes a bottleneck to thickness reduction.